He has built a living sun, collided Earth with a warring Fifth Dimension and even created a new type of time. Bizarrely, however, this is not Grant Morrison's most respected work - for the writer of DC's relaunched Justice League is also responsible for The Doom Patrol, Animal Man and The Invisibles. Together, they amount to some of the most challenging, stimulating and thought-provoking work ever produced in comic books.

However intimidating his work might sound, Morrison himself is a friendly and personable man. He speaks cheerfully and openly in a soft Glaswegian accent - as willing to talk about his childhood and girlfriends as he is to discuss the Mayan Calendar and his thoughts on the upcoming Apocalypse. Rumours that he looks just like the Invisibles' King Mob are only slightly exaggerated. He has a shaved head and wears leather, although it hangs on a rather lighter frame. His face is continually animated - it soon becomes clear that working in comics is a childhood dream realised.

"I've always known I wanted to write comics," he says with a smile. "It's strange. I mean the only other things that I wanted to be were a cowboy and an astronomer. And then I realised that my maths wasn't good enough for astronomy and cowboys were out of date."

"I guess it really started with my mum," he continues. "She took me round the back of the house one night and pointed up to the star Sirius. She said to me, 'Son that's where we come from'. I thought I'd better find out if she was lying. I still don't know, although I have my suspicions."

His mother was an avid fan of Star Trek and science fiction. He, however, was more interested in super-heroes. His uncle was a fan of Jack Kirby and Steve Ditko and had piles of Doctor Strange comics that the young boy read voraciously. And it wasn't long before he started to produce work of his own.

"I wrote my first thing when I was eight. It was a little book called 'The People of the Asteroid' and it was for my Mum's birthday. She's still got it. It was a Star Trek thing about a space crew who went to investigate bad news on an asteroid."

Near Myths, his first piece to achieve more conventional publication, appeared in the late seventies while Morrison was still at school. It featured the first appearance of Gideon Stargrave, a figure who would reappear in various guises throughout his career. He describes this early work sheepishly as "pretty embarrassing stuff - the work of a seventeen year old who doesn't get out of the house", but confesses that, "people seemed to like it - I went to a couple of conventions".

From then his life alternated between working at the English publisher DC Thompson doing 'space-commando' books and being on unemployment benefit. It was 1986 before he got to the cult British comic 2000 AD, and a couple more years before he created his first ongoing series. Zenith was both a popular and novel approach to super-heroes, and it caught the eye of American companies still reeling from the success of Alan Moore.

Morrison is deadpan about this transition: "It just so happened that DC were doing a trawl of the UK and I happened to be there at the time. It was enough that Zenith was a super-hero story - something they could relate to. I basically suggested that I should do Animal Man because it was so obscure that I didn't think anyone else would have thought of it."

The Animal Man project began as a four issue miniseries in what he describes with a laugh as the "Alan Moore style - lots of poetic captions and interesting scene transitions", but it soon spiralled away from this concept.

"Half-way through the first four issues I decided that I just couldn't continue with it. They had asked me to do it as an ongoing series, but it just wasn't the kind of thing that I wanted to do. Suddenly the idea of the 'Coyote Gospel' came to me and that basically set the template for everything that I've done since."

In this pivotal episode, Animal Man (Buddy Baker) stumbles into the middle of a battle between a gay man who has lost his partner and a huge were-creature that instantly recovers cartoon-style from any injury. The creature is Crafty Coyote, a character which clearly reflects Warner Brother's 'Wyle E'. He has been exiled from his cartoon existence by 'God' and now lives in Animal Man's world. By accepting a series of grotesque cartoon injuries, Crafty has brought peace to his own reality. He is finally destroyed - unable to explain the reason for his existence to his killer. As Buddy bends over his body, a huge hand comes from the sky to touch up the colour of the comic page.

Over the next twenty issues, Animal Man explores animal rights, is physically rebuilt from scratch and finally suffers the assassination of his wife and two children. Through a quest for answers that involves hallucinogens, comic book limbo and the coming of the second Crisis, he finally discovers that he is living in a comic book under the total control of a writer. And in the 25th issue he gets to confront his creator - meeting Morrison in Glasgow in what must be one of the most extraordinary conclusions to a story arc ever produced.

"I had immense freedom with Animal Man," Morrison explains. "There were only two stories that I couldn't do. One was a really radical animal rights story. It was probably a bit over the score in terms of violence and shock-value for DC. And there was another crazy 60s plot which didn't happen - although I was able to bring bits of it back later on. Apart from that they pretty much let me do what I wanted."

Morrison's fascination with fictional reality has become a central theme in The Invisibles, the three-volume epic that will reach its conclusion around the turn of the millennium. In many ways it is the natural end product of his work to date. He himself has called it the book he has always wanted to write. However, his original plans for the title were very different from the end result... (more tomorrow)